Redux Promise Bind

Promise Bind middleware for Redux.

npm install --save redux-promise-bind

Motivation

Redux Promise Bind middleware gives you more control over promises. Writing logic based on promises should be faster than using Redux Thunk or Redux Promise.

You dispatch object (that's why it is easy to test), and Redux middleware will trigger promise and dispatch appropriate actions (with _START, _SUCCESS or _ERROR action type suffixes) for you. So you don't need to make it manually (for example in thunk).

dispatch({
  type: 'GET',
  promise: axios.get.bind(null, ...attr)
})

Your action creator could be

function addItem(...attr) {
  return {
    type: 'ADD',
    promise: http.post.bind(null, '//url.com', ...attr)
  }
}

and Redux Promise Bind middleware will dispatch ADD_START action (you could for example show spinner) and after resolve promise will dispatch ADD_SUCCESS (or ADD_ERROR) with response data as a payload, so you could manage it by reducer.

Because promises are triggered by middleware, you have more control. You can keep your promises in queue or abort previous or next promises from the same group. You could also create your custom middleware to add more logic around.

Installation

npm install --save redux-promise-bind

To add Redux Promise Bind, use applyMiddleware (similar like others middlewares).

import { createStore, applyMiddleware } from 'redux'
import promiseBind from 'redux-promise-bind'
import rootReducer from './reducers/index'

// Note: this API requires redux@>=3.1.0
const store = createStore(
  rootReducer,
  applyMiddleware(promiseBind),
)

Usage

To handle action by Redux Promise Bind you need to dispatch action with promise attribute in body. It could for example ajax client.

Passing attributes to promise

You can bind attributes directly to your function

function actionCreator() {
  return {
    type: 'ACTION_TYPE',
    promise: yourFunction.bind(null, 'arg1', 'arg2')
  }
}

or you can pass them in promiseArg attribute

function actionCreator() {
  return {
    type: 'ACTION_TYPE',
    promise: yourFunction,
    promiseArg: ['arg1', 'arg2'],
  }
}

Access to response data in container

Because Redux Promise Bind Middleware returns promises and responses, you could have access to them in your container or in another middleware.

this.props.dispatch(
  myActionCreator(arg1)
).then((promiseResponse) => console.log(`data from promise ${promiseResponse}`))

Metadata and responses

Redux Promise Bind Middleware will dispatch actions with _START, _SUCCESS or _ERROR action types for you. Success promises response or error response will be kept in payload action parameter.

You can pass some metadata in metadata action parameter if you want to keep it in each generic action.

For example, you can dispatch action

{
  type: 'SAVE',
  promise: model.save,
  promiseArg: '123',
  metadata: { id: '123' },
}

model.save is function, which create HTTP request to save our data.

Redux Promise Bind Middleware immediately will dispatch action

{
  type: 'SAVE_START',
  metadata: { id: '123' },
}

so you can show spinner or show appropriate message. Metadata in this case could be helpful if you would like to have Redux store with states (isLoading, hasError) associated to ID.

After successful promise resolving (let's assume that model.save has returned success string) Redux Promise Bind Middleware immediately will dispatch action

{
  type: 'SAVE_SUCCESS',
  payload: 'success',
  metadata: { id: '123' },
}

If promise will throw an error (let's assume that model.save has returned error string) Redux Promise Bind Middleware immediately will dispatch action

{
  type: 'SAVE_ERROR',
  payload: 'error',
  metadata: { id: '123' },
}

For both responses you could for example change your Redux state and hide spinner for specific ID.

Group promises (TODO promise queue, takeLast, takeFirst)

License

MIT